Greekey

iTrader: (3)

I'm getting ready to put the valve train back together, and thought I would measure for pushrod length again just to be safe. I installed the adjustable pushrod making sure it was on the base circle of the camshaft and not touching the rocker. I torqued the rocker down to 22ft/lbs and then started adjusting the pushrod until I reached zero lash. I removed the rocker and pushrod making sure I did not turn the push rod while removing it. I am just shy of 9 full turns on the pushrod until it is fully closed. I am actually at 8 3/4 of turns until it is closed. Doing the math, I divided .050 by 4 and got .125 so 3/4 of a turn would put me at .375. So the real number of turns is 8.375 until it is closed. Doing the math, 8.375 x 0.050 + 6.800 would give me 7.220. Doesnt this sound odd? And doesnt it sound odd thats with zero lifter preload? I was planning on running a 0.075 preload and that would give me an overall length of 7.295. WTF??? My ls6 heads were milled .030, running ls7 lifters, and a Gm mls gasket.

Sales2@Texas-speed

iTrader: (5)

That's bad math It is 8.75 turns x .050" per turn = .4375 + 6.800" base length = 7.2375...that's your zero lash length. 7.300" would put you at .0625" of preload.

The thing that concerns me is that this week you've got a different zero lash length than last week....I'd do it again, and hope you repeat either the length from last week or this week.

Greekey

iTrader: (3)

Crap I meant 8.75 oops.

Greekey

iTrader: (3)

Okay since its a 7.2375 with no preload:

7.2375 with desired preload lengths:

.075 preload=7.3125 pushrod
.080 preload=7.3175 pushrod
.085 preload=7.3225 Pushrod
.090 preload=7.3275 Pushrod

So Ill be fine running a 7.325 pushrod correct? Do these numbers sound right? I actually checked and checked and got these results over and over again.

Scoggin Dickey

iTrader: (34)

I've come up with 7.300-7.325 on cars with milled LS6 heads, thin gaskets, and LS7 lifters in the past

Greekey

iTrader: (3)

And thats with preload correct?

Sales2@Texas-speed

iTrader: (5)

With your measurement, and using readily available pushrod lengths, here are the correlating preload values.

7.300" = 0.0625" preload
7.325" = 0.0875" preload
7.350" = 0.1125" preload

Greekey

iTrader: (3)

Thanks matt.

Scoggin Dickey

iTrader: (34)

Yes, I am talking pushrod length

blackmagicturbo

iTrader: (2)

Just outta curiosity ,,what is your retainer to seal clearance at max lift with 7.325 pushrod ?